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At least 685 records · Page 38Linked to original sources
PubMed1977

Respiratory control of body temperature: a theoretical model.

The two-compartment model of a ventilatory CO2 chemostat of Grodins et al. (1954) is modified to describe a ventilatory thermostat fitting the requirements of panting. Allowance for the extra heat production during panting leads to a second order third degree differential equation which by introducing the ventilation/perfusion ratio can be reduced to the second degree. From the steady-state solutions calculated for dogs using experimentally determined constants it is concluded that: (1) the ventilation/perfusion ratio has no influence; (2) the ambient temperature leads to a marked panting only above 30 degree C; (3) the relative humidity of the air increases the panting; (4) due to the oxygen cost of panting, the regulation of the body temperature is possible only within limits. The limitation depends upon the energy requirements of the respiratory muscles, upon the set-point temperature and the controller gain. The unsteady-state solution is given by approximation. The ventilatory reaction to the heat stress appears to be slow with a half-time of about 15 min for a 20 kg dog. All properties of the model are mainly determined by the high specific heat of tissues relative to expired air.

Animals↗
PubMedDate not supplied

A theoretical model of the perimenopausal process.

The purpose of this qualitative investigation was to generate theory grounded in the responses of perimenopausal women about the process of menopause. A purposive sample of 12 perimenopausal women was interviewed to discover the menopausal process. Data were generated from interviews, two-month daily logs, and field notes. A substantive theory of Integrating a Changing Me identified the perimenopausal process, which included four categories: Tuning Into Me, My Body and Moods, which described the awareness of physical and emotional changes that initiated the beginnings of menopause; Facing a Paradox of Feelings, which reflected the thoughts, perceptions, and feelings experienced by perimenopausal women. Contrasting Impressions, which described the assimilation of information and the formulation of the woman's own personal meaning; and Making Adjustments, which included changes made by the women in response to this process. Implications for health care and education of perimenopausal women are discussed.

Adaptation, Psychological↗